1. Field of the Invention
The disclosures herein generally relate to a system for realizing color management between color image output devices.
2. Description of the Related Art
Image processing that is referred to as color management is performed to match the color representations of various color image output devices such as a color monitor, a color printer, and a copier that output color images based on digital color image signals.
As color management techniques, the color management architecture promulgated by the ICC (International Color Consortium) and ICC profiles defining the corresponding data format are widely known.
In a color transformation process based on the ICC architecture, input image data is transformed from an input device color space to an output device color space via a device-independent color space that is referred to as PCS (Profile Connection Space).
In the ICC architecture, the CIE 1976 (L*, a*, b*) color space, the CIE 1931 XYZ color space, or PRMG (Perceptual Reference Media Gamut) corresponding to a stable reference space for the above color spaces may be used as the PCS.
The range of colors that may be reproduced by a device on the PCS is referred to as “gamut.” In color management, since the gamut of an input device and the gamut of an output device are different in most cases, gamut mapping has to be performed to rearrange the boundary of the gamut of the input device to be within the boundary of the gamut of the output device.
Since such gamut mapping process depends on the color attributes of the output device, in a case where plural printers with different gamuts can be used via a network, for example, if a user is to make color adjustments in contemplation of an output image of a selected printer, the user may have to reassess the color adjustment results each time the printer corresponding to the output destination is switched.
In this regard, Japanese Patent No. 3513334 discloses performing gamut mapping on a common gamut of plural output devices to match the color reproduction ranges of plural output devices. However, in the disclosed technique, the color reproduction range is limited to the common gamut of the plural output devices. Thus, in a case where an output destination may be selected from plural different types of output devices with different gamuts, the common gamut of the output devices may be too narrow with respect to the gamut of the input device.
It is noted that a user does not necessarily designate all available output devices as the output destination. That is, generally, a user designates only devices with a wide gamut as the output destination, or only devices with a narrow gamut as the output destination. Also, even when a combination of wide gamut devices and narrow gamut devices are designated as the output destinations, the output devices may have different priorities with respect to color reproduction. For example, certain output devices may have a high priority for color reproduction while other output devices may be used merely to check the layout of an output image. In practice, depending on the document to be output, there may be instances where a common color reproduction range is desired among the output destination devices and instances where the output devices have different priorities with respect to color reproduction.
It is particularly noted that when an output image of a wide gamut device is desired but a PSC that is narrower than the gamut of the output device is used, adequate saturation and contrast may not be reproduced. On the other hand, when an output image of a narrow gamut device is desired but a PSC with a wider gamut is used, the colors of the output image may be over-saturated.
Also, it is noted that the above described priorities with respect to color reproduction needs to be shared by members of a working group that work together through division of labor and collaboration to produce printed matter. However, when a dedicated PCS for a shared objective is not used, the PCS tends to be unnecessarily wide and it may be difficult to obtain a consensus among the members of the working group on the priorities with respect to color reproduction.